[RegCNET] Simulation stops due to CFL violation in-spite of decreasing dt

[SUDIPTA GHOSH]

Hello Enrique,

Firstly thank you for the suggestion.

But my resolution is ds=25km, 50km. According to the user guide the model
should work in hydrostatic core above ds=20km. Can you please help in the
fact?

On Thu, Aug 10, 2017 at 2:09 AM, Enrique Pazos <pazosenrique at gmail.com>
wrote:

> Dear Sudipta Ghosh,
>
> I ran into the same problem with high resolution (ds < 20 km). The problem
> was solved using the non-hydrostatic core, i.e. setting the parameter
>
> idynamic = 2
>
> I hope this helps.
>
> Regards,
>
> e.
>
> On Wed, Aug 9, 2017 at 2:06 AM, SUDIPTA GHOSH <sudiptaghosh006 at gmail.com>
> wrote:
>
>> Hello All,
>>
>> I tried to run a 5year simulation with RegCM4.5 with dx=25km and dt=30
>> secs but the model stopped due to CFL violation after 6month simulation. I
>> decreased the dt to 25, 20 and 15 still the job got killed due the same
>> reason, however the simulation period varied each time.
>>
>> Next I tried to run a 2 year simulation with RegCM4.4 at the same
>> combination of dx and dt but again the problem occurred. I even tried
>> changing the vertical levels from 18 to 23 but no run was completed.
>>
>> Next I changed the resolution to 50km and tried with following
>> combinations:
>>
>> ds=50km dt=150secs
>> ds=50km dt=120secs
>> ds=50km dt =100secs
>>
>> But the same error as above is persisting.
>>
>> I will be highly obliged if anyone can kindly advice for the same.
>>
>> I have tried to run the job on 360, 300, 240 and 200 processors as well.
>> However the message in each log file is as follows:
>>
>> WHUUUUBBBASAAAGASDDWD!!!!!!!!!!!!!!!!
>>  No more atmosphere here....
>>  CFL violation detected, so model STOP
>>  #####################################
>>  #            DECREASE DT !!!!       #
>>  #####################################
>>  WHUUUUBBBASAAAGASDDWD!!!!!!!!!!!!!!!!
>>  No more atmosphere here....
>>  CFL violation detected, so model STOP
>>  #####################################
>>  #            DECREASE DT !!!!       #
>>  #####################################
>>  Abort called by computing node          345 at 2017-05-08 18:29:32.161
>> +0530
>>  Abort called by computing node          329 at 2017-05-08 18:29:32.162
>> +0530
>> ------------------------------------------------------------
>> --------------
>> MPI_ABORT was invoked on rank 345 in communicator MPI COMMUNICATOR 3 DUP
>> FROM 0
>> with errorcode 1.
>>
>> NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
>> You may or may not see output from other processes, depending on
>> exactly when Open MPI kills them.
>>
>> --
>> Regards
>>
>> Sudipta Ghosh
>> PhD Scholar, Center for Atmospheric Sciences
>> Indian Institute of Technology Delhi,India.
>>
>> _______________________________________________
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>> RegCNET at lists.ictp.it
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>>
>
>
>
> --
> Enrique Pazos, Ph.D.
> Director Departamento de Postgrado
> Escuela de Ciencias Físicas y Matemáticas
> Universidad de San Carlos de Guatemala
> http://fisica.usac.edu.gt/~epazos/
>



-- 
Regards

Sudipta Ghosh
PhD Scholar, Center for Atmospheric Sciences
Indian Institute of Technology Delhi,India.
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